Cryptography is the practice and study of logical means used to achieve information confidentiality, integrity and authenticity. It covers, among other things, encryption (making some data unreadable except for those who know a given secret element, called a key), data hashing (in particular for ...

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1answer
65 views

how to find a cryptography scheme (either authentication or encryption) for which some formal analysis of security has not been done yet

I have a project in Cryptography where I have to discuss the provable security of any proposed scheme (encryption or authentication) which has not been discussed yet. Any pointers on how and where to ...
-1
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0answers
22 views

KakaoTalk message encryption [on hold]

I am trying to write a tool to decode the KakaoTalk chat application and the messages are encrypted with this pretty bizarre looking base64 'Lx7ZczQJ/sdOAw8DdFcauw==', That might possibly be a base64 ...
0
votes
1answer
101 views

Asymmetric vs Symmetric Encryption Benchmarks

I have found these benchmarks in Crypto++'s site. http://www.cryptopp.com/benchmarks.html But I am, quite honestly, not entirely sure how to interpret them. I am really looking for a set of ...
58
votes
8answers
122k views

How to determine what type of encoding/encryption has been used?

Is there a way to find what type of encryption/encoding is being used? For example, I am testing a web application which stores the password in the database in an encrypted format ...
1
vote
1answer
63 views

Calculating D-Wave's integer factorization capabilties

D-Wave has teased the ability to perform integer factorization previously, but if you jump to ~10:00 in this presentation they actually appear to outline how they can perform integer factorization ...
0
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1answer
719 views

What is the deal with Valicert SSL root certificates?

Does anyone know what the status of the "Valicert Class 2 Validation Authority" root certificate is or what's going on with Valicert in general? I've heard that that cert has been deprecated, no ...
80
votes
6answers
26k views

Password Hashing add salt + pepper or is salt enough?

Please Note: I'm aware that the proper method for secure password storage hashing is either scrypt or bcrypt. This question isn't for implementation in actual software, it's for my own understanding. ...
292
votes
11answers
52k views

How to securely hash passwords?

If I hash passwords before storing them in my database, is that sufficient to prevent them being recovered by anyone? I should point out that this relates only to retrieval directly from the ...
0
votes
0answers
123 views

Gladman's file encryption library = AES in counter mode with HMAC-SHA1 authentication?

I would like to use Gladman's algorithm to create AES encrypted data in JavaScript. I use the Crypto-JS library, but its performance is horrible. PBKDF2 is terribly slow, so I switched to another ...
0
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0answers
575 views

OpenSSL: Bad Record MAC on TLS Heart Beat

I am trying to see the heartbleed bug in action with my OpenSSL server application. My server uses the OpenSSL library - openssl-1.0.1b I successfully connect with s_client (openssl-1.0.1b) to my ...
0
votes
0answers
30 views

DTLS CertificateVerify doubt

In DTLS 1.2 RFC 6347, section 4.2.6: CertificateVerify and Finished messages have the same format as in TLS. Hash calculations include entire handshake messages, including DTLS-specific fields: ...
0
votes
0answers
126 views

RSA 4096 key size difference - “sig” and “sig 3”

Whenever I generate a new 4096 RSA key in my GPG program and export the public key to a text file, I get a text file containing a total of around 52 lines (it varies, one of them is 53 lines). ...
6
votes
3answers
687 views

How can I prove that I wrote a certain blog post?

I would like to be able to prove that I wrote the article that resides at a given URL on someone else's blog. Is there a way that I can do this with public key cryptography? I know a bit about the ...
2
votes
1answer
258 views

Requiring 2 keys to access a content

I need to use an external service that can only be accessed by password. I don't like the idea of storing the plaintext password on the server, but AFAIK there's not much I can do. Considering this ...
24
votes
6answers
25k views

Asymmetric vs Symmetric Encryption

I am currently taking a principles of information security class. While talking about different encryption methods a large number of my classmates seem to believe that Asymmetric Encryption is better ...
7
votes
1answer
61 views
+50

What concrete parameters can I change to make my passphrase-protected private gpg key more secure

There are several questions which discuss the resistance of passphrase-protected private gpg keys against brute force attacks. It seems, this kind of discussion could go on forever. Rather than ...
38
votes
3answers
4k views

Is Git crowdsourcing cryptographic attacks?

A strong cryptographic hash makes collisions unlikely. Many cryptographic protocols build on that fact. But Git is using SHA-1 hashes as object identifiers. So there are a lot of already computed ...
9
votes
4answers
4k views

Is Changing a File Type and Name an Effective Security Solution?

Is renaming folders & files and changing file types an effective solution for file security of a PC? I am an application programmer and have an extensive background in it. I have written a ...
0
votes
0answers
35 views

Suggestion of encrypt method for short fixed size result

I'm searching for a encrypt method that receives an int variable and outputs exactly 11 hexadecimal digits. I'm starting on a existing application, that already has a database of more than 130.000 ...
0
votes
1answer
54 views

Integrity-Based Execution

Intrusion Detection Systems (IDS) rely on binary signatures or known-bad-behavior of malware in order to detect threats. It has become very clear that this approach has limited success due to the fact ...
6
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3answers
264 views

Decentralised password recovery

Are there good/established techniques for password/key recovery in situations without a centralised service? (Anything goes, but I'd prefer solutions that distribute the recovery information across ...
29
votes
5answers
51k views
2
votes
2answers
64 views

Why is GPG encrypted message size not proportional to number of recipients & file size?

I have noticed that when I am using GnuPG to encrypt a file for multiple recipients, the size of the encrypted message does not seem to be directly proportional to the number of recipients. For ...
0
votes
1answer
86 views

Publicly Available API + Sensitive ID/Key Transmission Over HTTP

I've run into a predicament... I'm developing a mobile application that utilizes a server for various things. One portion is that it stores an id/key pair related to accessing and processing ...
4
votes
2answers
295 views

Including and storing the order of character entry in a password as an enhanced security measure

I'm sure I will be quickly corrected if this is a stupid idea, or if it has already been tried. My question is: has this idea been tried before? If not, are there good reasons it would not work, or ...
7
votes
1answer
470 views

Is there a method to get plain-text from cipher-text in HMAC SHA-1, given that the key is known?

This is technically not even an attack. We have all the resources at hand, except for the original plain-text. We have the cipher-text (to be converted back to plain-text), as well as the key. The ...
2
votes
3answers
134 views

Are there any flaws in this two way cryptographic function?

I created a simple two way cryptographic function which allows you to encrypt a message and decrypt it with the same key. Here's how it works. Split the message into an array of 32-bit (or something ...
1
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0answers
45 views

Public keys Quality

Is there any way to test the quality of generated keys from a public key cryptosystem? I've read about the common RSA attacks, but attacking the algorithm may not mean checking if the generated keys ...
-2
votes
0answers
15 views

How to compare security parameters of different schemes (Sign-Encrypt, Encrypt-Sign, etc)? [migrated]

How can one compare the security parameters (confidentiality, integrity, non repudiation, etc.) for different schemes (Sign-Encrypt, Encrypt-Sign, Sign-Encrypt-Sign, Encrypt-Sign-Encrypt)? Are there ...
0
votes
1answer
145 views

How to secure my REST API once user authenticates with Google on mobile client?

In my application, I build REST APIs so that user can interact with my application server. Since I do not want to maintain User/Passwords, my iOS app authenticates client using Google. This all ...
0
votes
4answers
190 views

How safe is it to use older/unknown Encryption methods for plaintext?

When mailing or chatting with people, it had crossed my mind, what if, for simple communication, someone would use an older encryption method (i.e., ENIGMA), to encrypt their message? Would because ...
1
vote
2answers
65 views

Using OAuth 2.0 without token storage

I am building a system for a product which requires Authentication and Authorization. Naturally I have chosen using OAuth 2.0 as it is a commonly used protocol and has proven to be useful. I am ...
21
votes
4answers
3k views

How would you store a 4 digit pin code securely in the database?

I'm familiar with password hashing, using salts, bcrypt etc. But it doesn't seem like this would work to store a 4 digit pin code since the attacker could try all 10,000 combinations quite quickly. ...
0
votes
3answers
177 views

How strong is a simple XOR encryption with random IV?

I'd like to implement some kind of simple (yet as strong as possible) encryption for my client-server application network traffic. Data to be encrypted can be both textual, and binary. Now I'm ...
1
vote
1answer
63 views

How to store derby database encryption key in HSM?

The Derby Database supports encryption with a key or password. Traditionally this key is stored in the file systems, now I am looking to store and protect this key in the HSM instead, but I couldn't ...
3
votes
2answers
239 views

Continued Use of Kerberos

I posted this question over on Crypto.SE, but didn't get any takers and thought it might be more suited for this site as it were, so I'm cross posting it here. I was recently looking through the Mac ...
9
votes
3answers
2k views

Suitable cipher for SMS encryption

I would like to create application for encrypting SMS messages. After long enough discussions I decided to use symmetric encryption, since handling public/private keys issue is too difficult for most ...
0
votes
1answer
63 views

Can a botnet be used to effectively break encryption keys?

Can a botnet amass and coordinate enough computing power to break encryption keys that are typically considered to be secure (through brute force)? If this is the case, do we need to make our ...
-1
votes
1answer
43 views

Calculating the breakability of a given encryption method

I will soon be doing a very important project for school. The main goal of my project is to find a mathematical way to calculate the breakability of a given encryption method of ciphertext. Is there ...
4
votes
4answers
456 views

How widely deployed is TLS with cipher ECDHE?

Microsoft deployed a patch for Windows 2012 R2 and Windows 8.1 that adds the following ciphers. Cipher suite Exchange Encryption Hash TLS_DHE_RSA_WITH_AES_256_GCM_SHA384 DH ...
1
vote
1answer
81 views

NaCL: Encrypt file to multiple recipients

I am trying to understand the Networking And Cryptography Library (NaCL). Consider i have a file that i want to send to multiple recipients. PGP or S/MIME supports multiple recipients by encrypting ...
1
vote
2answers
142 views

What is DVNC and how does it work?

As stated on their website: DVNC is not encryption but is a new branch of cryptography and information science. DVNC employs a new paradigm in secret keeping to keep your data secured. I ...
0
votes
1answer
55 views

Why do we encrypt ephemeral Public key in Encrypted Key Exchange

Encrypted Key Exchange can resist off-line dictionary attack Protocol : A ---> B : Ep (PK) B ---> A : Ep(Epk(K)) K is Session Key generated by B PK is an ephemeral public key ...
2
votes
4answers
377 views

How to prove to friend I have solution to puzzle (without revealing it)? [closed]

My friend Paul set me this arithmetic puzzle: To make 21 from the numbers 1, 5, 6, 7. You can use the operations add, subtract, multiply, divide as well as brackets. You must use each number once. ...
1
vote
1answer
98 views

How are SHA1 and MD5 considered to not protect against collisions?

SHA1 and MD5 hash functions are considered to not protect against collisions while SHA2 is. Is it the size of the message digest that makes this or the algorithm itself? If it is based on the message ...
11
votes
3answers
9k views

License key / Serial number generator and checker

I need a serial number generator and accompanying checker. I would like to be able to set a salt (and maybe a length). The generator should only produce serial numbers that pass the test of the ...
1
vote
1answer
78 views

How can you check if a private key and certificate match in OpenSSL with ECDSA?

I know how to do this with RSA keys (see this article: Determine if private key belongs to certificate?) however I do not know how to do this for ECDSA certificate / key pairs. With RSA keys, the ...
0
votes
0answers
22 views

Rabin Cryptosystem Problem (variant) [migrated]

My understanding of Rabin We have p and q which are distinct primes congruent to 3 mod 4. Then we have n = p*q. Encryption is done as e(m) = m^2 mod n, where m is our message. Decryption is done ...
16
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2answers
2k views

Flaw in encryption through pseudorandom number stream (from PGP documentation)

I was reading PGP docs and came upon a part written by Phil Zimmermann (PGP's creator) that piqued my curiosity: When I was in college in the early 70s, I devised what I believed was a brilliant ...
126
votes
8answers
12k views

Why are salted hashes more secure?

I know there are many discussions on salted hashes, and I understand that the purpose is to make it impossible to build a rainbow table of all possible hashes (generally up to 7 characters). My ...